Frequency Of Thyroid Nodules Detected In Euthyroid Type2Diabetic Patients Treated With Different Hypoglycemic Agents

Objectives：To investigate if the use of anti-diabetic drugs including metformin，insulin，insulinotropic agents，other oral antidiabetic agents affect the presence ofthyroid nodules in euthyroid patients with type2diabetes mellitus (T2DM).Methods：Two hundred and twenty patients with T2DM (men/women117/103)hospitalized for poor glycemic control in the author’s hospital during August,2013toFebruary,2014were enrolled. All patients were examined with color ultrasound forexistence of thyroid nodules.159patients with thyroid nodules were found(men/women85/74). Patients were subgrouped into six groups according to theirhypoglycemic modalities, before admission for at least one year: Group A, patients whoused only metformin (n=60); Group B, only insulinotropic agents (n=20); Group C,only insulin (n=60); Group D, insulin with metformin (n=32); Group E, insulin withother oral antidiabetic agents except metformin and insulinotropic agents (n=14);GroupF, other oral antidiabetic agents in combination or only (mostly acarbose)(n=34).Results：1. The frequncy of thyroid nodules in this study group of patients with type2diabetes mellitus was found to be72.3%, and there was trend toward a higher frequencyin older (OR=1.031,95%CI:1.004-1.058, P=0.022), patients with longer duration ofdiabetes (OR=1.078,95%CI:1.023-1.137, P=0.005), and higher level of fasting insulin(OR=0.966,95%CI:0.938-1.009, P=0.033).2. Different hypoglycemic modalities showed differences in body massindex(F=2.366, P=0.041), triglyceride (F=4.172, P=0.001), insulin resistance index(F=3.083, P=0.01), duration of diabetes (F=10.696, P=0.000). There were nosignificant differences for sex, age, fasting blood glucose,2h postprandial blood glucose,cholesterol, high-density lipoprotein cholesterol, low density lipoprotein cholesterol,apolipoprotein A, apolipoprotein B, high sensitive CRP, thyrotropin, duration of currentanti-diabetic drugs therapy.3. Patients treated only with metformin had a lower incidence of thyroid nodulesthan with other anti-diabetic drugs. The frequency of thyroid nodules found patientgroups with different anti-diabetic drugs was statistically significant different (P＜0.05).Compared with patients with alone metformin, the frequency of thyroid nodules ingroup with insulin, group with insulin with metformin were higher (63.9%vs80%and84.4%, P＜0.05), while no differences were found in group with insulinotropic agents,in group with insulin with other oral antidiabetics, and in group with other oralantidiabetics (P＞0.05). Using group with metformin as a reference, logistic regression analysis was conducted to analyze hazard risk between thyroid nodules and differenthypoglycemic modalities, no significant difference was found in frequency of thyroidnodules found in group only with metformin against other groups after adjusted withsex, age, body mass index, thyrotropin, duration of diabetes, duration of anti-diabeticdrugs therapy.Conclusion: The frequency of thyroid nodules detected was common inhospitalized euthyroid patients with type2diabetes.Longer duration of diabetes,advanced age, higher level of insulin increased thyroid nodules frequency. Noassociation was found among different hypoglycemic agents with development ofthyroid nodules. The main limitation of our study was the small number of people, andneeds larger sample to be surveyed in future.